"""Unit tests for currency_conversion service."""

from datetime import date

from odoo.tests.common import TransactionCase, tagged
from odoo.addons.fusion_accounting_reports.services.currency_conversion import (
    convert_amount, fetch_rates,
)


@tagged('post_install', '-at_install')
class TestCurrencyConversion(TransactionCase):

    def test_same_currency_returns_unchanged(self):
        result = convert_amount(100, source_currency='USD',
                                target_currency='USD',
                                rate_date=date(2026, 4, 19), rates={})
        self.assertEqual(result, 100)

    def test_direct_rate(self):
        rates = {('USD', 'CAD', date(2026, 4, 19)): 1.35}
        result = convert_amount(100, source_currency='USD',
                                target_currency='CAD',
                                rate_date=date(2026, 4, 19), rates=rates)
        self.assertEqual(result, 135)

    def test_inverse_rate(self):
        rates = {('CAD', 'USD', date(2026, 4, 19)): 0.74}
        result = convert_amount(100, source_currency='USD',
                                target_currency='CAD',
                                rate_date=date(2026, 4, 19), rates=rates)
        self.assertAlmostEqual(result, 100 / 0.74, places=2)

    def test_falls_back_to_most_recent_rate(self):
        rates = {
            ('USD', 'CAD', date(2026, 1, 1)): 1.30,
            ('USD', 'CAD', date(2026, 3, 1)): 1.32,
        }
        result = convert_amount(100, source_currency='USD',
                                target_currency='CAD',
                                rate_date=date(2026, 4, 19), rates=rates)
        self.assertEqual(result, 132)

    def test_raises_when_no_rate(self):
        with self.assertRaises(ValueError):
            convert_amount(100, source_currency='EUR',
                           target_currency='CAD',
                           rate_date=date(2026, 4, 19), rates={})

    def test_fetch_rates_from_env(self):
        cad = self.env.ref('base.CAD')
        rates = fetch_rates(self.env, target_currency_id=cad.id, as_of=date(2026, 4, 19))
        self.assertIsInstance(rates, dict)